将卡刷到最喜欢的项目

Question

当我偶然发现这个视频时,我正在查看Google的Material文档.它显示了一个卡片项目,可以向右滑动以收藏项目.

我想镜像这种行为但多次失败.我能找到的所有库和教程都是关于swipe-to-delete.我试图将两个视图堆叠在一起,其中顶部的一个应该被刷,以便下面的一个可见.我尝试用这个来实现这个ItemTouchHelper,但是这个类似乎只能促进swipe-to-delete和move重新排序列表操作.

如何实现此滑动操作？

Answer 1

你需要使用 ItemTouchHelper

• 这是一个实用程序类,用于添加滑动dismiss和拖放支持RecyclerView.
• 它适用于一个RecyclerView和一个Callback类,它配置启用哪种类型的交互,并在用户执行这些操作时接收事件.

下面是示例代码如何使用ItemTouchHelper与RecyclerView

StackActivity

import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.helper.ItemTouchHelper;
import java.util.ArrayList;

public class StackActivity extends AppCompatActivity {


    RecyclerView myRecyclerView;
    private ArrayList<ItemModel> arrayList = new ArrayList<>();
    FavAdapter favAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_stack);

        myRecyclerView = findViewById(R.id.myRecyclerView);
        myRecyclerView.setLayoutManager(new LinearLayoutManager(this));
        myRecyclerView.setHasFixedSize(true);

        // here i'm adding dummy data inside list
        addDataInList();

        // setting adapter to RecyclerView
        favAdapter = new FavAdapter(this, arrayList);
        myRecyclerView.setAdapter(favAdapter);

        new ItemTouchHelper(new ItemTouchHelper.SimpleCallback(0, ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT) {
            @Override
            public boolean onMove(@NonNull RecyclerView recyclerView, @NonNull RecyclerView.ViewHolder viewHolder, @NonNull RecyclerView.ViewHolder target) {
                return false;
            }

            @Override
            public void onSwiped(@NonNull RecyclerView.ViewHolder viewHolder, int direction) {

                // when user swipe thr recyclerview item to right remove item from avorite list
                if (direction == ItemTouchHelper.RIGHT) {
                    favAdapter.addToFav(viewHolder.getAdapterPosition(), false);
                }
                // when user swipe thr recyclerview item to left remove item from avorite list
                else if (direction == ItemTouchHelper.LEFT) {
                    favAdapter.addToFav(viewHolder.getAdapterPosition(), true);
                }

            }
        }).attachToRecyclerView(myRecyclerView);


    }


    //method to add dummy data inside ourlist
    private void addDataInList() {

        arrayList.add(new ItemModel("Item 1", "https://i.stack.imgur.com/1dWdI.jpg", false));
        arrayList.add(new ItemModel("Item 2", "https://i.stack.imgur.com/1dWdI.jpg", false));
        arrayList.add(new ItemModel("Item 3", "https://i.stack.imgur.com/1dWdI.jpg", false));
        arrayList.add(new ItemModel("Item 4", "https://i.stack.imgur.com/1dWdI.jpg", false));
        arrayList.add(new ItemModel("Item 5", "https://i.stack.imgur.com/1dWdI.jpg", false));
        arrayList.add(new ItemModel("Item 6", "https://i.stack.imgur.com/1dWdI.jpg", false));
        arrayList.add(new ItemModel("Item 7", "https://i.stack.imgur.com/1dWdI.jpg", false));
        arrayList.add(new ItemModel("Item 8", "https://i.stack.imgur.com/1dWdI.jpg", false));
        arrayList.add(new ItemModel("Item 9", "https://i.stack.imgur.com/1dWdI.jpg", false));
        arrayList.add(new ItemModel("Item 10", "https://i.stack.imgur.com/1dWdI.jpg", false));
        arrayList.add(new ItemModel("Item 11", "https://i.stack.imgur.com/1dWdI.jpg", false));
        arrayList.add(new ItemModel("Item 12", "https://i.stack.imgur.com/1dWdI.jpg", false));
        arrayList.add(new ItemModel("Item 13", "https://i.stack.imgur.com/1dWdI.jpg", false));
        arrayList.add(new ItemModel("Item 14", "https://i.stack.imgur.com/1dWdI.jpg", false));
        arrayList.add(new ItemModel("Item 15", "https://i.stack.imgur.com/1dWdI.jpg", false));
        arrayList.add(new ItemModel("Item 16", "https://i.stack.imgur.com/1dWdI.jpg", false));
        arrayList.add(new ItemModel("Item 17", "https://i.stack.imgur.com/1dWdI.jpg", false));
        arrayList.add(new ItemModel("Item 18", "https://i.stack.imgur.com/1dWdI.jpg", false));
        arrayList.add(new ItemModel("Item 19", "https://i.stack.imgur.com/1dWdI.jpg", false));
        arrayList.add(new ItemModel("Item 20", "https://i.stack.imgur.com/1dWdI.jpg", false));
    }

}

activity_stack布局

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/myRecyclerView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>

</LinearLayout>

FavAdapter类

import android.content.Context;
import android.support.annotation.NonNull;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import com.bumptech.glide.Glide;
import com.bumptech.glide.request.RequestOptions;

import java.util.ArrayList;

public class FavAdapter extends RecyclerView.Adapter<FavAdapter.ViewHolder> {
    private Context context;
    private ArrayList<ItemModel> arrayList = new ArrayList<>();

    public FavAdapter(Context context, ArrayList<ItemModel> arrayList) {
        this.context = context;
        this.arrayList = arrayList;
    }

    @NonNull
    @Override
    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(context).inflate(R.layout.custom_fav_layout, parent, false);
        return new ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {


        // here i'm check that if item is already added in favorite  or not
        //based on boolean flag i'm managed to set weather the item is in favorite or not
        // this flag is also use full to keep state of out favorite when we scroll our recyclerview
        holder.ivFavImage.setImageResource(arrayList.get(position).isFavorite()
                ? R.drawable.ic_favorite : R.drawable.ic_fav_white);


        holder.tvProductName.setText(arrayList.get(position).getItemName());

        Glide.with(context)
                .load(arrayList.get(position).getImageUrl())
                .apply(new RequestOptions().
                        placeholder(R.drawable.ic_placeholder)
                        .error(R.drawable.ic_error))
                .into(holder.ivProductImage);
    }

    // this method is used to add or remove item from favorite list when use swipe the recyclerview item using ItemTouchHelper
    public void addToFav(int position, boolean flag) {
        arrayList.get(position).setFavorite(flag);
        notifyDataSetChanged();
    }


    @Override
    public int getItemCount() {
        return arrayList.size();
    }

    public class ViewHolder extends RecyclerView.ViewHolder {

        ImageView ivProductImage, ivFavImage;
        TextView tvProductName;

        public ViewHolder(View itemView) {
            super(itemView);

            ivProductImage = itemView.findViewById(R.id.ivProductImage);
            ivFavImage = itemView.findViewById(R.id.ivFavImage);
            tvProductName = itemView.findViewById(R.id.tvProductName);


            ivFavImage.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    if (arrayList.get(getAdapterPosition()).isFavorite()) {
                        arrayList.get(getAdapterPosition()).setFavorite(false);
                    } else {
                        arrayList.get(getAdapterPosition()).setFavorite(true);
                    }
                    notifyDataSetChanged();
                }
            });
        }
    }
}

custom_fav_layout布局

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:cardElevation="5dp"
    app:cardUseCompatPadding="true">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <ImageView
            android:id="@+id/ivProductImage"
            android:layout_width="match_parent"
            android:layout_height="150dp"
            android:scaleType="fitXY"
            android:adjustViewBounds="true"
            android:src="@color/colorNavBar" />


        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:orientation="horizontal">

            <TextView
                android:id="@+id/tvProductName"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:text="@string/app_name"
                android:paddingStart="5dp"
                android:textColor="#FFFFFF"
                android:textStyle="bold" />

            <ImageView
                android:id="@+id/ivFavImage"
                android:layout_width="50dp"
                android:layout_height="50dp"
                android:src="@drawable/ic_favorite" />

        </LinearLayout>


    </RelativeLayout>

</android.support.v7.widget.CardView>

ItemModel damodel类

public class ItemModel {


   boolean isFavorite;
   String ItemName,imageUrl;

    public ItemModel( String itemName, String imageUrl,boolean isFavorite) {
        this.isFavorite = isFavorite;
        ItemName = itemName;
        this.imageUrl = imageUrl;
    }

    public boolean isFavorite() {
        return isFavorite;
    }

    public void setFavorite(boolean favorite) {
        isFavorite = favorite;
    }

    public String getItemName() {
        return ItemName;
    }

    public void setItemName(String itemName) {
        ItemName = itemName;
    }

    public String getImageUrl() {
        return imageUrl;
    }

    public void setImageUrl(String imageUrl) {
        this.imageUrl = imageUrl;
    }
}

R.drawable.ic_favorite

<vector xmlns:android="http://schemas.android.com/apk/res/android"
        android:width="24dp"
        android:height="24dp"
        android:viewportWidth="24.0"
        android:viewportHeight="24.0">
    <path
        android:fillColor="#FF00"
        android:pathData="M12,21.35l-1.45,-1.32C5.4,15.36 2,12.28 2,8.5 2,5.42 4.42,3 7.5,3c1.74,0 3.41,0.81 4.5,2.09C13.09,3.81 14.76,3 16.5,3 19.58,3 22,5.42 22,8.5c0,3.78 -3.4,6.86 -8.55,11.54L12,21.35z"/>
</vector>

drawable.ic_fav_white

<vector xmlns:android="http://schemas.android.com/apk/res/android"
    android:width="24dp"
    android:height="24dp"
    android:viewportWidth="24.0"
    android:viewportHeight="24.0">
    <path
        android:fillColor="#FFFFFF"
        android:pathData="M12,21.35l-1.45,-1.32C5.4,15.36 2,12.28 2,8.5 2,5.42 4.42,3 7.5,3c1.74,0 3.41,0.81 4.5,2.09C13.09,3.81 14.76,3 16.5,3 19.58,3 22,5.42 22,8.5c0,3.78 -3.4,6.86 -8.55,11.54L12,21.35z"/>
</vector>

以上示例代码的输出

https://www.youtube.com/watch?v=GKD-SDPWD3k&feature=youtu.be

有关信息,您可以查看以下文章

• Android将RecyclerView Swipe添加到删除和撤消
• 使用RecyclerView的Android滑动菜单
• RecyclerView滑动删除比您想象的更容易
• Android RecyclerView滑动以删除示例按钮并撤消
• Android RecyclerView:可滑动项目

如果你想去任何图书馆而不是检查这个

• SwipeToDelete
• 滑动式-RecyclerView
• itemtouchhelper扩展